/* 学習記録システム 共通スタイル（/admin, /teacher 共通） */

:root {
  --color-bg: #f7f7f5;
  --color-surface: #ffffff;
  --color-border: #e0e0dc;
  --color-text: #222222;
  --color-text-sub: #666666;
  --color-primary: #2b6cb0;
  --color-primary-text: #ffffff;
  --color-danger: #c0392b;
  --color-warning: #b7791f;
  --color-warning-bg: #fff8e1;
  --color-success: #2f855a;

  --understanding-1: #e53e3e;
  --understanding-2: #ed8936;
  --understanding-3: #ecc94b;
  --understanding-4: #68d391;
  --understanding-5: #38a169;

  --tap-min-height: 48px;
  --font-min-size: 16px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Yu Gothic', sans-serif;
  font-size: var(--font-min-size);
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
}

body {
  padding-bottom: env(safe-area-inset-bottom, 0);
}

button, input, select, textarea {
  font-family: inherit;
  font-size: var(--font-min-size);
}

button {
  min-height: var(--tap-min-height);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  cursor: pointer;
  padding: 12px 16px;
}

button:active {
  opacity: 0.8;
}

button.primary {
  background: var(--color-primary);
  color: var(--color-primary-text);
  border-color: var(--color-primary);
  font-weight: bold;
}

button.selected {
  background: var(--color-primary);
  color: var(--color-primary-text);
  border-color: var(--color-primary);
}

button.danger {
  background: var(--color-danger);
  color: #fff;
  border-color: var(--color-danger);
}

input[type="text"], input[type="number"], textarea {
  min-height: var(--tap-min-height);
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
}

.app-container {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 12px;
}

.card-alert {
  background: var(--color-warning-bg);
  border-color: var(--color-warning);
}

.stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.grade-heading {
  font-size: 14px;
  color: var(--color-text-sub);
  margin: 20px 0 8px;
  font-weight: bold;
}

.student-btn {
  width: 100%;
  text-align: left;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: stretch;
}

.student-btn .student-name {
  font-size: 18px;
  font-weight: bold;
}

.student-btn .student-last-log {
  font-size: 13px;
  color: var(--color-text-sub);
}

.understanding-row {
  display: flex;
  gap: 8px;
}

.understanding-btn {
  flex: 1;
  min-height: 56px;
  font-size: 22px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.understanding-btn[data-level="1"].selected { background: var(--understanding-1); border-color: var(--understanding-1); }
.understanding-btn[data-level="2"].selected { background: var(--understanding-2); border-color: var(--understanding-2); }
.understanding-btn[data-level="3"].selected { background: var(--understanding-3); border-color: var(--understanding-3); }
.understanding-btn[data-level="4"].selected { background: var(--understanding-4); border-color: var(--understanding-4); }
.understanding-btn[data-level="5"].selected { background: var(--understanding-5); border-color: var(--understanding-5); }

.bottom-fixed {
  position: sticky;
  bottom: 0;
  background: var(--color-bg);
  padding: 12px 0;
  border-top: 1px solid var(--color-border);
}

.section-title {
  font-weight: bold;
  margin-bottom: 8px;
}

.instructor-highlight {
  color: var(--color-primary);
  font-weight: bold;
}

.text-sub {
  color: var(--color-text-sub);
  font-size: 13px;
}

.loading, .empty {
  text-align: center;
  color: var(--color-text-sub);
  padding: 24px 0;
}